Method, apparatuses and computer program for reporting in-device coexistence information

ABSTRACT

Methods and apparatus for control of a device with coexisting radios and capable of carrier aggregation are disclosed. A change in the activation status of a secondary cell can be determined where after interference information to be reported is determined in response to the determined change. The determined interference information is compared to interference information reported previously for a similar change, and a decision is made based thereon whether to send the determined interference information. In a network entity interference information received from at least one device is stored. The stored interference information is used in the control when it is determined that no interference information is received subsequent to a new change in the activation status of the secondary cell.

This disclosure relates to reporting in a wireless communication systemand more particularly to reporting of information in relation to awireless device provided with coexisting radios.

A communication system provides a facility that enables communicationsessions between two or more entities such as fixed or mobilecommunication devices, base stations, servers, machine type devices,and/or other communication nodes. A communication system and compatiblecommunicating entities typically operate in accordance with a givenstandard and/or specification setting out how the various entities shalloperate. In a wireless communication system at least a part of thecommunication between at least two devices, or stations occurs over awireless interface. Examples of wireless systems include public landmobile networks (PLMN) such as cellular networks, satellite basedcommunication systems and different wireless local networks, for examplewireless local area networks (WLAN). A wireless connection can also beprovided by short range radio, for example based on the Bluetooth™radio.

An example of wireless communication systems is an architecture that isbeing standardized by the 3rd Generation Partnership Project (3GPP).This system is often referred to as the long-term evolution (LTE) of theUniversal Mobile Telecommunications System (UMTS) radio-accesstechnology. A further development of the LTE is often referred to asLTE-Advanced. The various development stages of the 3GPP LTEspecifications are referred to as releases.

Communications can be provided between appropriate communicationdevices. In a wireless system a communication device can provide atransceiver station that can communicate with another communicationdevice such as e.g. base stations of access networks and/or other userequipment. A communication device of a user is often referred to as userequipment (UE) or terminal. A communication device is provided with anappropriate signal receiving and transmitting arrangement for enablingcommunication of data and signalling with other parties. For example,access to a communication network or communications directly with otherusers can be provided. The communication device may access a carrierprovided by a station, for example a base station providing art leastone cell, and transmit and/or receive communications on the carrier.Carrier aggregation can be used to increase performance. In carrieraggregation a plurality of carriers are aggregated to increasebandwidth. Carrier aggregation comprises aggregating a plurality ofcomponent carriers into a carrier that is referred to in thisspecification as an aggregated carrier. For example, LTE-Advanced iscapable of providing carrier aggregation. In LTE-A two or more componentcarriers (CCs) can be aggregated in order to support wider transmissionbandwidths and/or for spectrum aggregation. Depending on itscapabilities, it is possible to configure a user equipment (UE) toaggregate a different number of component carriers, either originatingfrom the same location or from different ones, and/or either from thesame frequency band or different ones. A primary component carrier canbe provided by a primary cell (PCell) whereas further carriers can beprovided by at least one secondary cell (SCell). SCells form togetherwith the PCell a set of serving cells. To enable reasonable batteryconsumption by the user equipment when aggregating carriers, anactivation/deactivation mechanism of SCells is supported. When an SCellis deactivated, it is not necessary for the user equipment to receivethe corresponding physical downlink control channel (PDCCH) or physicaldownlink shared channel (PDSCH). Also, in this state the user equipmentcannot transmit in the corresponding uplink and nor is it required forit to perform channel quality indicator (CQI) measurements. Conversely,when an SCell is active, the user equipment shall receive PDSCH andPDCCH (if the user equipment is configured to monitor PDCCH from thisSCell), and is expected to be able to perform CQI measurements.

A communication device can be provided with a multiple of coexistingradios in order to allow users to access various networks and servicesubiquitously. For example, a wireless communication device can beequipped with multiple radio transceivers. The number of such devices isincreasing. In accordance with a more particular example a mobile devicemay be equipped with a cellular radio (e.g. LTE), a wireless local areanetwork (e.g. WiFi™), and a short range radio (e.g. Bluetooth™)transceivers, and global navigation satellite system (GNSS) receivers.This can cause problems in view of interference, and more particularly,coexistence interference between the collocated radio transceivers.In-device coexistence (IDC) interference can occur for example whentransmitting in one frequency band interferes with receiving in anotherband within the same equipment. For example, due to the proximity ofmultiple radio transceivers, the transmit power of one transmitter maybe much higher than the received power level of another receiver. Bymeans of filter technologies and sufficient frequency separation, thetransmit signal may not result in significant interference. But for somecoexistence scenarios, e.g. different radio technologies within the samedevice operating on adjacent frequencies, current state-of-the-artfilter technology might not provide sufficient rejection. Therefore,solving the interference problem by a single generic radio frequency(RF) design may not always be possible and alternative methods may needto be considered.

A base station serving a mobile device can be used to mitigate theeffect of coexistence interference. One of the proposals for avoidanceof in-device coexistence interference in relation to the LTE is for theuser equipment to signal information to the radio access network basedon which a controller associated with the base station can made decisionsuch as when transmission/reception or other radio signal would benefitor no longer benefit from not using certain carriers or frequencyresources. A more particular example is known as a Frequency DomainMultiplexing (FDM) Solution. In accordance with this solution anIndustrial, Scientific and Medical (ISM) radio signal is led away fromLTE frequency band in frequency domain. The arrangement may also need toavoid coexistence interference to ISM radio during an initial stage tohelp the ISM radio to complete the necessary procedure to enable thisoption. Another example for avoidance of in-device coexistenceinterference is known as a time domain multiplexing (TDM) solution. Inthe TDM scheduled and unscheduled periods are alternated on theproblematic frequencies to ensure that transmission of a signal does notcoincide with reception of another signal. To provide control based one.g. FDM and/or TDM principles, the access system relies on informationsignalled from the user equipment to the network element, which in LTEwould be evolved NodeB (eNB). Based on such information, final TDMpatterns (i.e. scheduled and unscheduled periods) relying on DRX can beconfigured by the eNB. For the FDM solution, the user equipment canindicate which frequencies are unusable due to in-device coexistence. Inresponse to such signalling, an eNB can then take appropriate action,for example order a handover to a frequency that has not been reportedas suffering from in-device coexistence interference

In the following description, the information reported by the userequipment to assist the access system in solutions such as the FDM andTDM will be referred to as in-device coexistence (IDC) information. Inthe standards this information can be referred to asInDeviceCoexIndication.

When features such as carrier aggregation (CA) is combined with IDCinformation reporting, situations where the content of IDC informationchanges can occur relatively frequently, depending on the changes in theactivation activation status of a secondary cell (SCell) and as aresult, whenever the activation status of an SCell changes, the userequipment always needs to report new IDC information to the network.

Embodiments of the invention aim to address one or several of the aboveissues.

It is noted that the issues are not limited to any particularcommunication system, standard, specification, radios and so forth, butmay occur in any communication device and/or system where a device canbe provided with coexisting radios.

In accordance with an embodiment there is provided a method for a devicewith coexisting radios and capable of carrier aggregation, comprisingdetermining a change in the activation status of a secondary cell,determining interference information to be reported in response to thedetermined change in the activation status of the secondary cell,comparing the determined interference information to be reported tointerference information reported previously for a similar change in theactivation status of the secondary cell, and deciding whether to sendthe determined interference information based on the comparison.

In accordance with an embodiment there is provided a method for anetwork entity for control of at least one device with coexisting radiosand capable of carrier aggregation, comprising storing interferenceinformation received from the at least one device in response to achanged activation status of a secondary cell, determining a new changein the activation status of the secondary cell, determining whetherinterference information is reported in response to the new change inthe activation status of the secondary cell, and using the storedinterference information in the control when it is determined that nointerference information is received subsequent to the new change in theactivation status of the secondary cell.

In accordance with an embodiment there is provided a method for a devicewith coexisting radios and capable of carrier aggregation, comprisingdetermining interference information assuming a given activation statusfor at least one secondary cell in a configured set of cells, andreporting the determined interference information to a network for usein controlling the device. The given change may be assumed for allsecondary cells in the configured set.

In accordance with an embodiment there is provided an apparatus forcontrolling a device with coexisting radios and capable of carrieraggregation, the apparatus comprising at least one processor, and atleast one memory including computer program code, wherein the at leastone memory and the computer program code are configured, with the atleast one processor, to determine a change in the activation status of asecondary cell, determine interference information to be reported inresponse to the determined change in the activation status of thesecondary cell, compare the determined interference information to bereported to interference information reported previously for a similarchange in the activation status of the secondary cell, and decidewhether to send the determined interference information based on thecomparison.

In accordance with an embodiment there is provided an apparatus for anetwork entity for control of at least one device with coexisting radiosand capable of carrier aggregation, the apparatus comprising at leastone processor, and at least one memory including computer program code,wherein the at least one memory and the computer program code areconfigured, with the at least one processor, to store interferenceinformation received from the at least one device in response to achange in the activation status of a secondary cell, determine a newchange in the activation status of the secondary cell, determine whetherinterference information is reported in response to the new change inthe activation status of the secondary cell, and use the storedinterference information in the control when it is determined that nointerference information is received subsequent to the new change in theactivation status of the secondary cell.

In accordance with an embodiment there is provided an apparatus for adevice with coexisting radios and capable of carrier aggregation, theapparatus comprising at least one processor, and at least one memoryincluding computer program code, wherein the at least one memory and thecomputer program code are configured, with the at least one processor,to determine interference information assuming a given activation statusfor at least one secondary cell on a configured set of cells, and reportthe determined interference information to a network for use incontrolling the device.

In accordance with an aspect the interference information comprisesin-device coexistence interference information. The change in activationstatus may comprise activation or deactivation of the secondary cell.Interference information may be reported in response to the change inthe activation status only when there is different information contentto be reported compared to previous reporting for similar change.

A base station such as an eNB or a user equipment implementing theembodiments may also be provided.

A computer program comprising program code means adapted to perform theherein described methods may also be provided. In accordance withfurther embodiments apparatus and/or computer program product that canbe embodied on a computer readable medium for providing at least one ofthe above methods is provided.

Various other aspects and further embodiments are also described in thefollowing detailed description of examples embodying the invention andin the attached claims.

The invention will now be described in further detail, by way of exampleonly, with reference to the following examples and accompanyingdrawings, in which:

FIG. 1 shows an example of a communication system wherein belowdescribed examples of the invention may be implemented;

FIG. 2 shows an example of a communication device;

FIG. 3 shows an example of a multi-radio communication device;

FIG. 4 shows an example of controller apparatus for a base station; and

FIGS. 5 to 7 are flowcharts illustrating certain embodiments.

In the following certain exemplifying embodiments are explained withreference to a wireless or mobile communication system serving mobilecommunication devices. Therefore, before explaining in detail theexemplifying embodiments, certain general principles of a wirelesscommunication system, components thereof, and mobile communicationdevices are briefly explained with reference to FIGS. 1 to 4 to assistin understanding the technology underlying the described examples.

A mobile communication device 21 is typically provided wireless accessvia at least one access node such as a base station, a remote radio heador similar wireless transceiver node. In FIG. 1 base station 20 andremote radio head 40 provide each a radio service area or a cell of acellular system. The cell borders are shown schematically by the ovalshaped patterns, and only for illustration purposes. It is also notedthat a great number of radio service areas may be provided in acommunication system and that a mobile communication device maysimultaneously be located in a plurality of cellular service areas.Also, the transceiver node sites 20 and 40 can each provide more thanone cell and/or a plurality of sectors, for example three radio sectors,each sector providing a cell or a sub radio service area of a cell. Forthe purposes of the examples described herein, the cell provided by basestation 20 can be seen as a primary cell (PCell) and the cell providedby the remote radio head 40 as a secondary cell (SCell). The exampleshown uses the remote radio head for the secondary cell for clarity, andit is noted that a secondary cell can also be provided by otherstations, for example by the same base station 20 providing the primarycell.

A transceiver node is typically controlled by at least one appropriatecontroller so as to enable operation thereof and management of mobilecommunication devices in communication with the station. The controlapparatus can be interconnected with other control entities. In FIG. 1 acontrol apparatus of base station 20 is shown schematically as beingprovided by block 30. A suitable control apparatus can be provided withmemory capacity 31 and at least one data processor 32. The controlapparatus and functions may be distributed between a plurality ofcontrol units.

A non-limiting example of communication systems is the long-termevolution (LTE) of the Universal Mobile Telecommunications System (UMTS)that is standardized by the 3rd Generation Partnership Project (3GPP). ALTE base station is known as evolved or enhanced NodeB (eNB) in thevocabulary of the 3GPP specifications. LTE based systems can employ amobile architecture known as the Evolved Universal Terrestrial RadioAccess Network (E-UTRAN). Other examples of radio services providing amobile device with access to a communication system include thoseprovided by stations of systems that are based on technologies such aswireless local area network (WLAN) and/or WiMax (WorldwideInteroperability for Microwave Access). WLANs are sometimes referred toby WiFi™, a trademark that is owned by the Wi-Fi Alliance, a tradeassociation promoting Wireless LAN technology and certifying productsconforming to certain standards of interoperability.

In FIG. 1 example stations 20 and 40 are connected to a widercommunications network 35. A controller may be provided for coordinatingthe operation of the access systems. A gateway function may also beprovided to connect to another network via the network 35. The othernetwork may be any appropriate network. A wider communication system maythus be provided by one or more interconnect networks and the elementsthereof, and one or more gateways may be provided for interconnectingvarious networks. Stations 20 and 40 are connected for signallingpurposes, as indicated by the connection 39. The connection between thebase stations may involve intermediate nodes of one or more cellularnetworks.

The mobile communication device 21 may further communicate with forexample another mobile device 36. This communication may be provided bymeans of a short range link, for example, by means of Bluetooth™connectivity. FIG. 1 also shows a satellite 38 with which the mobiledevice 21 may receive and/or receive and transmit radio signals. Thesatellite may be a satellite of a positioning system or a satellite of asatellite based communication system.

FIG. 2 shows a schematic, partially sectioned view of a communicationdevice 21 that a user can use for communication. Such a communicationdevice is often referred to as user equipment (UE) or terminal. Anappropriate mobile communication device may be provided by any devicecapable of sending and receiving radio signals. Non-limiting examplesinclude a mobile station (MS) such as a mobile phone or what is known asa ‘smart phone’, a portable computer provided with a wireless interfacecard or other wireless interface facility, personal data assistant (PDA)provided with wireless communication capabilities, or any combinationsof these or the like. A mobile communication device may provide, forexample, communication of data for carrying communications such asvoice, electronic mail (email), text message, multimedia, positioningdata, other data, and so on. Users may thus be offered and providednumerous services via their communication devices. Non-limiting examplesof these services include two-way or multi-way calls, data communicationor multimedia services or simply an access to a data communicationsnetwork system, such as the Internet.

A mobile device is typically provided with at least one data processingentity 23, at least one memory 24 and other possible components 29 foruse in software and hardware aided execution of tasks it is designed toperform, including control of access to and communications with stationsof the network and other communication devices. The data processing,storage and other relevant control apparatus can be provided on anappropriate circuit board and/or in chipsets. This feature is denoted byreference 26. Data processing and memory functions provided by thecontrol apparatus of the mobile device to cause control and signallingoperations in accordance with certain embodiments of the presentinvention will be described later in this description.

The user may control the operation of the mobile device by means of asuitable user interface such as key pad 22, voice commands, touchsensitive screen or pad, combinations thereof or the like. A display 25,a speaker and a microphone are also typically provided. Furthermore, amobile communication device may comprise appropriate connectors (eitherwired or wireless) to other devices and/or for connecting externalaccessories, for example hands-free equipment, thereto.

The mobile device 21 may receive and transmit signals 28 via appropriateapparatus for receiving and transmitting signals. In FIG. 2 transceiverapparatus is designated schematically by block 27. The transceiver maybe provided for example by means of a radio part and associated antennaarrangement. The antenna arrangement may be arranged internally orexternally to the mobile device. A wireless communication device can beprovided with a Multiple Input/Multiple Output (MIMO) antenna system. Amore detailed example of possible radio components is shown in FIG. 3.

In order to allow users to access various communication systems andservices ubiquitously, a user equipment can be equipped with multiplecoexisting radio transceivers. However, this can cause interference, andmore particularly, coexistence interference between those collocatedradio transceivers. In-device coexistence interference can occur forexample when transmitting in one frequency band interferes withreceiving in another, within the same user equipment. FIG. 3 shows anexample of coexistence interference in a multi-radio device. Due to theproximity of multiple radio transceivers within the same device, thetransmit power of one transmitter may be much higher than the receivedpower level of another receiver, and this can cause interference.

In the example of FIG. 3, a device 21 has a first antenna 50, a secondantenna 52 and a third antenna 54. The first antenna 50 is configured totransmit and receive LTE signals. The second antenna 52 is configured toreceive GPS (global positioning system) signals. The third antenna 54 isconfigured to transmit and receive Bluetooth™ and/or Wi-Fi™′ signals.The first antenna 50 is connected to an LTE radio frequency processor 56which is arranged to process the radio frequency signals. The LTE radiofrequency processor 56 is coupled to an LTE baseband processor 66 whichis arranged to process the radio frequency signals to convert thosesignals to the baseband and to process those signals. Similarly, thesecond antenna 52 is coupled to a GPS radio frequency processor 58,which is arranged to be coupled to the GPS baseband processor 64.Finally, the third antenna 54 is connected to a Bluetooth™/Wi-Fi™ radiofrequency processor 60 which in turn is connected to theBluetooth™/Wi-Fi™ baseband processor 62. It should be appreciated thatwhen the respective antenna receives a radio frequency signal, thatradio frequency signal is provided to the respective radio frequencyprocessor. The radio frequency processor may carry out any suitableprocesses, for example, filtering the desired signal from the undesiredsignals and/or amplification. The processed radio frequency signal isthen provided to the respective baseband processor for down-conversionto the baseband and further processing. In the case of transmission, thebaseband processors will receive the signals at the baseband andup-convert those signals to the radio frequency. Other processing may becarried out by the baseband processors. Those radio frequency signalsare then passed to the respective radio frequency processor.

The processing carried out by the respective blocks can be performed bya single block or processor, or by more than two blocks or processors.The division of the processes between the blocks can of course bechanged. For example, the RF processing block may, for example, in someembodiments perform the baseband conversion, at least one of convertingdown to the baseband or up-converting to the radio frequency. Separateprocessors and/or antennas may be provided in some embodiments foruplink and downlink. In some embodiments, at least one processor may beused for two or more different types of signal received from and/or tobe transmitted by two or more antennas. It should be appreciated that insome embodiments, the GPS blocks may only need to receive signals.

It is possible that when LTE and Industrial, Scientific and Medical(ISM; this can include technologies such as the Bluetooth™ and WLAN)radio capabilities are provided in a single device, the LTE and ISMradio within the same device may be working on adjacent frequencies. Forexample, the LTE may be working on the upper part of band 40 (2300-2400MHz) and the ISM may be working in the example 2450 MHz band. This typeof coexistence may cause interference. This interference between thedifferent frequencies is schematically shown in FIG. 3 by arrowed dashedlines 68 and 70. This interference can be addressed by e.g. the FDM andTDM techniques discussed above.

FIG. 4 shows an example of a control apparatus 30, for example to becoupled to and/or for controlling a station of a radio service area, forexample one of the stations 20 and 40 of FIG. 1. The control apparatus30 can be arranged to process and/or control signalling and othercommunications by mobile communication devices in a service area of astation. The control apparatus 30 can be configured to provide controlfunctions in association with communication, storage and use of IDCinformation. The control apparatus can control operation of mobiledevices within its service area based on information communicated inaccordance with certain embodiments described below, for example fordisabling one or more of the radios and/or using a differentconfiguration pattern during a handover. For providing the control thecontrol apparatus 30 can comprise at least one memory 31, at least onedata processing unit 32, 33 and an input/output interface 34. Via theinterface the control apparatus can be coupled to receiver andtransmitter apparatus of a base station. The control apparatus 30 can beconfigured to execute an appropriate software code to provide thecontrol functions.

As explained above, to provide control based on e.g. FDM and/or TDMprinciples, the access system relies on IDC information signalled fromthe mobile devices to the network entity, for example eNB. For the TDMsolution, the IDC information can comprise e.g. information elementssuch as drx-CycleLength, drx-Offset and drx-ActiveTime. Based on suchIDC information, final TDM patterns (i.e. scheduled and unscheduledperiods) relying on discontinuous reception (DRX) can be configured bythe eNB. For the FDM solution, the mobile devices can indicate whichfrequencies are unusable due to in-device coexistence. For example,affectedCarrierFregList and interferenceDirection elements can be sent.In response to such signalling, an eNB can take appropriate controlaction, for example order one or more of the devices to perform ahandover to a frequency that has not been reported as suffering fromin-device coexistence interference. In certain embodiments, in order tominimise the amount of reporting, only new IDC information is sent bythe user equipment. Thus, a new IDC information is sent by the userequipment only if the content of IDC information changes compared towhat has been reported in the previous occurrence of IDC information.

When the activation status of a serving cell changes the mobile devicemay have to report updated IDC information to the network. In some ofthe embodiments IDC information is reported, stored and used in controlof the mobile devices depending on whether there is a change in theinformation compared to what has been previously reported for similarchange in activation status.

FIG. 5 is a flowchart in accordance with an embodiment for operation ofa device with coexisting radios and capable of carrier aggregation thatcommunicated with at least cell at 80. It is determined at 81 that thereis a change in the activation status of a secondary cell. The device canthen determine at 82 interference information, for example IDCinformation, to be reported in response to the determined change in thestate of the secondary cell. The determined interference information tobe reported is compared at 83 to interference information that has beenreported previously for a similar change is the activation status of thesecondary cell. Based on determination at 84 whether there is a changebetween the two sets of interference information, it is decided eitherto send the determined IDC information based on the determination, see85, or refrain from sending the determined interference information, see86. For example, at SCell activation, a new IDC information is reportedonly if the content of the report would be new compared to the last timeIDC information was sent when that SCell was activated. Similarly, atSCell deactivation, a new IDC information is reported only if thecontent of the report would be new compared to the last time IDCinformation was sent when that SCell was deactivated.

FIG. 6 shows operation at a network entity receiving at 90 theinformation for use in control of at least one device with coexistingradios and capable of carrier aggregation. Interference informationdetermined by and received from at least one device is stored at 91. Anew change in the activation status of a secondary cell for at least onedevice is ordered at 92. It can then be determined at 93, in response tothe change in the status, whether interference information has beenreported by the at least one device in response to the new change in theactivation status of the secondary cell. The interference informationreceived earlier and stored at 91 for a similar activation status changeis then used in the control when it is determined that no interferenceinformation is received subsequent to the new change in the activationstatus of the secondary cell, as shown by 95. If a report is received,then information contained in the report is used, as shown by 94.

FIG. 7 shows operation in a device with coexisting radios and capable ofcarrier aggregation in accordance with another embodiment. In themethod, when interference information, for example IDC information, isdetermined, a predefined or given activation the activation status isassumed for at least one available secondary cell, regardless what thestatus is in reality. In accordance with a possibility, all secondarycells of a set of configured cells for a device are considered to be inactivated state at 100. This does not necessarily mean that theactivation will take or has taken place, but only the effect of apossible activation of all cells is always taken into account. In otherwords, the reporting of interference information at 101 always considersany SCell belonging to the set of serving cells as being activated.

Alternatively, when IDC information is determined, the activation statusof the secondary cells of the set of configured cells can always beconsidered as de-activated. The determined IDC information is thenoblivious to possible changes activation status of SCells.

Since only new IDC information is reported, it follows that changes inthe activation status of an SCell alone cannot change the content of IDCinformation and therefore this does not trigger sending of IDCinformation.

The serving eNB can be made aware whether the received informationconsiders all SCells as activated, or deactivated, as the case may be,and can thus provide the control accordingly, without receiving IDCinformation reports for each status change.

The interference information can comprise in-device coexistence (IDC)interference information. The mobile device can be configured to havefurther restrictions in its triggering mechanisms of sending of an IDCinformation report. The mobile device detects that there is a change inthe activation status and in response sends the IDC report. The mobiledevice report new IDC information at SCell activation or deactivationonly if the content of the report is new compared to the last time IDCinformation was sent, e.g. the last time when that SCell was activatedor deactivated in such a manner that the information changed. This inits part enables combined use of IDC and carrier aggregation CA inresolving the potential increase in overhead that is possible because anactivation/deactivation changes the configuration of the user equipmentreceiver resulting a situation where, every time anactivation/deactivation command is given, an updated IDC informationwould be sent by the user equipment. This can translate into substantialoverhead since the user equipment is likely to toggle between tworeports: one when an SCell is activated and another when an SCell isdeactivated. By determining IDC information reporting such thatactivation/deactivation does not necessarily always trigger an IDCinformation update from the user equipment can be used to resolve thisissue, and the embodiments can be used to decrease potential uplinkoverhead.

The eNB is configured to maintain a record what information was reportedto it the last time the relevant SCell was activated/deactivated.

Thus, when IDC information changes at SCell activation/deactivation,only new/changed information is reported to the eNB. By keeping a recordin a memory thereof regarding information that was reported the lasttime when relevant SCells were activated/deactivated, the eNB knows whatto expect whenever it activates an SCell.

According to another embodiment reporting of IDC information can bemodified to take into account the possibility of activation of allSCells belonging to a configured set of serving cells. When all SCellsare always considered as activated when reporting is made, it may not benecessary to communicate IDC information from the user equipment eachtime, if at all, after activation/deactivation. This kind of operationmay be desired e.g. to guarantee that whenever an SCell is activated,the IDC information remains valid because the reporting always considersall SCells as activated. This embodiment may not as such allow fordifferentiating between activated and deactivated states but on theother hand can provide stable operation.

The various embodiment above can be provided as alternatives or ascomplementary solutions.

The required data processing apparatus and functions of a base stationapparatus, a communication device and any other appropriate station orelement may be provided by means of one or more data processors. Thedescribed functions at each end may be provided by separate processorsor by an integrated processor. The data processors may be of any typesuitable to the local technical environment, and may include one or moreof general purpose computers, special purpose computers,microprocessors, digital signal processors (DSPs), application specificintegrated circuits (ASIC), gate level circuits and processors based onmulti core processor architecture, as non limiting examples. The dataprocessing may be distributed across several data processing modules. Adata processor may be provided by means of, for example, at least onechip. Appropriate memory capacity can also be provided in the relevantdevices. The memory or memories may be of any type suitable to the localtechnical environment and may be implemented using any suitable datastorage technology, such as semiconductor based memory devices, magneticmemory devices and systems, optical memory devices and systems, fixedmemory and removable memory.

An appropriately adapted computer program code product or products maybe used for implementing the embodiments, when loaded or otherwiseprovided on an appropriate data processing apparatus, for example forcausing determinations when, what and where to communicate andcommunications of information between the various nodes. The programcode product for providing the operation may be stored on, provided andembodied by means of an appropriate carrier medium. An appropriatecomputer program can be embodied on a computer readable record medium. Apossibility is to download the program code product via a data network.In general, the various embodiments may be implemented in hardware orspecial purpose circuits, software, logic or any combination thereof.Embodiments of the inventions may thus be practiced in variouscomponents such as integrated circuit modules. The design of integratedcircuits is by and large a highly automated process. Complex andpowerful software tools are available for converting a logic leveldesign into a semiconductor circuit design ready to be etched and formedon a semiconductor substrate.

It is noted that whilst embodiments have been described in relation tocommunications system such as those based on the LTE systems and 3GPPbased systems, similar principles can be applied to other communicationsystems and channels where in-device interference may occur. Forexample, this may be the case in applications where no fixed stationequipment is provided but a communication system is provided by means ofa plurality of user equipment, for example in adhoc networks. Instead ofthe secondary cell being provided by at least one remote radio head orthe like, the secondary cell may also be provided by at least one otherbase station apparatus such as an eNB. Also, the above principles canalso be used in networks where relay nodes are employed for relayingtransmissions between stations. Therefore, although certain embodimentswere described above by way of example with reference to certainexemplifying architectures for wireless networks, technologies andstandards, embodiments may be applied to any other suitable forms ofcommunication systems than those illustrated and described herein. It isalso noted that different combinations of different embodiments arepossible. It is also noted herein that while the above describesexemplifying embodiments of the invention, there are several variationsand modifications which may be made to the disclosed solution withoutdeparting from the spirit and scope of the present invention.

The invention claimed is:
 1. A method, comprising performing operationsfor a device with coexisting radios, wherein for carrier aggregation oneradio connects to a primary cell and another radio connects to asecondary cell, the operations comprising: determining a change in theactivation status of the secondary cell, determining interferenceinformation to be reported in response to the determined change in theactivation status of the secondary cell, wherein the interferenceinformation comprises in-device coexistence interference information,comparing the determined interference information to be reported tointerference information reported previously for a similar change in theactivation status of the secondary cell, deciding whether to send thedetermined interference information based on the comparison, anddeciding to send and sending the determined interference information inresponse to the change in the activation status only when there isdifferent information content to be reported compared to previousreporting for a similar change, wherein the determined interferenceinformation is for use by the network element for control of the devicefor carrier aggregation.
 2. A method as claimed in claim 1, wherein thechange in activation status comprises activation or deactivation of thesecondary cell.
 3. A method as claimed in claim 1, wherein the devicecommunicates via at least one of a long-term evolution of the UniversalMobile Telecommunications System radio, an Industrial, Scientific andMedical radio, a local wireless access radio, short range link radio, asatellite system radio, and a positioning system radio.
 4. A method,comprising performing operations in a network entity for control forcarrier aggregation of at least one device with coexisting radios,wherein for carrier aggregation one radio of the at least one deviceconnects to a primary cell corresponding to the network entity andanother radio of the at least one device connects to a secondary cell,the operations comprising storing interference information received fromthe at least one device in response to a changed activation status of asecondary cell, wherein the interference information comprises in-devicecoexistence interference information, determining, after the storing, anew change in the activation status of the secondary cell, determiningwhether new interference information is received in response to the newchange in the activation status of the secondary cell, and using thestored interference information in the control of the at least onedevice for carrier aggregation in response to a determination that nonew interference information is received subsequent to the new change inthe activation status of the secondary cell, and wherein interferenceinformation is reported in response to the change in the activationstatus only when there is different information content to be reportedcompared to previous reporting for similar change.
 5. A method asclaimed in claim 4, wherein the change in activation status comprisesactivation or deactivation of the secondary cell.
 6. A method as claimedin claim 4, wherein the at least one device communicates via at leastone of a long-term evolution of the Universal Mobile TelecommunicationsSystem radio, an Industrial, Scientific and Medical radio, a localwireless access radio, short range link radio, a satellite system radio,and a positioning system radio.
 7. An apparatus comprising at least oneprocessor, and at least one memory including computer program code,wherein the at least one memory and the computer program code areconfigured, with the at least one processor, to perform operations for adevice with coexisting radios, wherein for carrier aggregation one radioconnects to a primary cell and another radio connects to a secondarycell, the operations comprising: determine a change in the activationstatus of the secondary cell, determine interference information to bereported in response to the determined change in the activation statusof the secondary cell, wherein the interference information comprisesin-device coexistence interference information, compare the determinedinterference information to be reported to interference informationreported previously for a similar change in the activation status of thesecondary cell, decide whether to send the determined interferenceinformation based on the comparison, and decide to send and send thedetermined interference information in response to the change in theactivation status only when there is different information content to bereported compared to previous reporting for a similar change, whereinthe determined interference information is for use by the networkelement for control of the device for carrier aggregation.
 8. Anapparatus as claimed in claim 7, wherein the change in activation statuscomprises activation or deactivation of the secondary cell.
 9. Anapparatus as claimed in claim 7, wherein the device is adapted tocommunicate via at least one of a long-term evolution of the UniversalMobile Telecommunications System radio, an Industrial, Scientific andMedical radio, a local wireless access radio, short range link radio, asatellite system radio, and a positioning system radio.
 10. A userequipment comprising an apparatus as claimed in claim
 7. 11. Anapparatus comprising at least one processor, and at least one memoryincluding computer program code, wherein the at least one memory and thecomputer program code are configured, with the at least one processor,to perform operations in a network entity for control for carrieraggregation of at least one device with coexisting radios, wherein forcarrier aggregation one radio of the at least one device connects to aprimary cell and another radio of the at least one device connects to asecondary cell, the operations comprising store interference informationreceived from the at least one device in response to a change in theactivation status of a secondary cell, wherein the interferenceinformation comprises in-device coexistence interference information,determine, after the storing, a new change in the activation status ofthe secondary cell, determine whether new interference information isreported in response to the new change in the activation status of thesecondary cell, and use the stored interference information in thecontrol of the at least one device for carrier aggregation in responseto a determination that no new interference information is receivedsubsequent to the new change in the activation status of the secondarycell, and wherein interference information is reported in response tothe change in the activation status only when there is differentinformation content to be reported compared to previous reporting forsimilar change.
 12. A base station comprising an apparatus accordingclaim
 11. 13. A base station as claimed in claim 12, comprising anevolved Node B.
 14. A computer program product comprising anon-transitory computer medium comprising program code adapted to causea data processing apparatus to perform the method of claim 1 when theprogram is run on the data processing apparatus.
 15. A computer programproduct comprising a non-transitory computer medium comprising programcode adapted to cause a data processing apparatus to perform the methodof claim 4 when the program is run on the data processing apparatus.